Note the addition of import datetime and from django.utils import timezone, to reference Python’s standard datetime module and Django’s time-zone-related utilities in django.utils.timezone, respectively. If you aren’t familiar with time zone handling in Python, you can learn more in the time zone support docs.

We could add it to part two too, but there is a point in which trying to support readers that attack the tutorial starting at arbitrary places e.g. part two without having followed part one isn't practical because it is detrimental to readability.